Over on the HP support forum there's a huge thread which suggest that HP might be having issues with the HP Elite Pavilion range of PCs which use the Intel Core i7 processor.
The thread is some 98 pages long and was begun when the problems started to come to light in July. Affected PCs freeze, lock up and BSoD on a regular basis, sometimes after as little as 15 minutes of use. Most of the complains seem to involve the HP Pavilion Elite e9150t but e9180t owners have also complained of similar issues. I've also come across owners of m9600 and e9100 series systems who are complaining of similar problems.
These issues don't seem to be random mishaps either. Some affected users report having received several replacement systems, with each system eventually starting to display similar symptoms after a few days. To make matters worse, some people have had to wait weeks for their replacement "defective" system to arrive.
Some users claim that the problem is due to defective resistors on the Pegatron IPMTB-TK motherboard (Pegatron was spun off from ASUS back in January 2008 when the company was restructured). Certainly sounds plausible.
Some observations:
I'll do some more digging on Monday.